Smoke is the main cause of fire death. In order to minimize the potential danger of smoke hazard, a rational VR based fire training simulator should fully consider all aspects of smoke hazard. In the simulator, the vi...Smoke is the main cause of fire death. In order to minimize the potential danger of smoke hazard, a rational VR based fire training simulator should fully consider all aspects of smoke hazard. In the simulator, the visualization of data based on FDS (Fire Dynamics Simulator) and FED fire dynamic data and volume rendering is further optimized, which can be effectively and quickly applied to virtual fire protection. In addition, a comprehensive smoke hazard assessment model based on FED and FED is established to assess the IHD value of different paths, which represents the safety of different paths, and can be used for evacuation or rescue in virtual training. Taking the case of campus fire drill as an experiment, the research shows the accuracy and effectiveness of smoke assessment based on FDS and FED model. The road force with the highest safety can be selected through the comprehensive model. So the assessment model is proved to be valuable.展开更多
Developing a localized and consistent model framework for climate loss and damage assessment is crucial for the policy-making of climate change mitigation and adaptation.This study introduces a comprehensive,multidisc...Developing a localized and consistent model framework for climate loss and damage assessment is crucial for the policy-making of climate change mitigation and adaptation.This study introduces a comprehensive,multidisciplinary Integrated Assessment Model(IAM)framework for evaluating climate damage in China,utilizing BCC-SESM climate model and FUND sectoral climate damage model under the SSP2-RCPs scenario.Employing a bottom-up approach,the research estimates climate damage across eight major sectors,recalibrates sectoral climate damage functions and parameters for China,and elucidates distinctions among direct climate loss,market climate loss,and aggregate climate loss.The findings reveal that the total climate damage function for China follows a quadratic pattern in response to temperature rise.By 2050,the estimated climate damage is projected to be 5.4%,5.7%,and 8.2%of GDP under RCP2.6,RCP4.5,and RCP8.5,respectively.Additionally,both direct and market climate losses are projected to remain below 2%of GDP by 2050,while the aggregate climate loss could reach as high as 8.2%,which is predominantly attributed to non-market sectors.From a sectoral perspective,under the RCP8.5 scenario,human health damage constitutes the largest share(61.9%)of the total climate loss by 2050,followed by sea-level rise damage(18.6%).This study sheds lights on the adaptation policy that should attach importance to the non-market sectors,particularly focusing on human health and sea-level rise.展开更多
Water yield, water supply and quality, wildlife habitat, and ecosystem productivity and services are important societal concerns for natural resource management in the 21st century. Watershed-scale ecohydrologic studi...Water yield, water supply and quality, wildlife habitat, and ecosystem productivity and services are important societal concerns for natural resource management in the 21st century. Watershed-scale ecohydrologic studies can provide needed context for addressing complex spatial and temporal dynamics of these functions and services. This study was conducted on the 5240 ha Turkey Creek watershed (WS 78) draining a 3rd order stream on the Santee Experimental Forest within the South Carolina Atlantic Coastal Plain, USA. The study objectives were to present the hydrologic characteristics of this relatively undisturbed, except by a hurricane (Hugo, 1989), forested water-shed and to discuss key elements for watershed management, including water resource assessment (WRM), modeling integrated water resources management, environmental assessment, land use planning, social impact assessment, and information management. Runoff coefficients, flow duration curves, flood and low flow frequency curves, surface and ground water yields were assessed as elements of the WRM. Results from the last 10 years of interdisciplinary studies have also advanced the understanding of coastal ecohydrologic characteristics and processes, water balance, and their modeling including the need of high resolution LiDAR data. For example, surface water dynamics were shown to be regulated primarily by the water table, dependent upon pre- cipitation and evapotranspiration (ET). Analysis of pre- and post-Hugo streamflow data showed somewhat lower but insignificant (α = 0.05) mean annual flow but increased frequency of larger flows for the post-Hugo compared with the pre-Hugo level. However, there was no significant difference in mean annual ET, potentially indicating the resiliency of this coastal forest. Although the information from this study may be useful for comparison of coastal ecohydrologic issues, it is becoming increasingly clear that multi-site studies may be warranted to understand these complex systems in the face of climate change, sea level rise, and increasing development in coastal regions.展开更多
Estimation of parameters and random effects using true maximum likelihood methods is compared to the commonly used penalized maximum likelihood method. The simulated catch-at-age datasets have all conceivable noise in...Estimation of parameters and random effects using true maximum likelihood methods is compared to the commonly used penalized maximum likelihood method. The simulated catch-at-age datasets have all conceivable noise in stock and fishing dynamics in addition to the observation error on the catch. Improvement is modest in simple models but refinements that are only possible with these methods provide additional precision. Unbiased estimation of natural mortality is made possible with these methods, but precision is low unless variation in fishing effort between years is large and other variation small, in particular the uncertainty in the recruitment. Relatively unbiased estimates of all other in-put parameters and variances were obtained. Alternately the stock may be updated with the catches directly, rather than through the fishing mortality. This can be done exactly and such that bias in the final stock is small. Such a model will test a different error structure and may also be more appealing for presentation of results as the catches are in better agreement with the changes in the estimated stock.展开更多
文摘Smoke is the main cause of fire death. In order to minimize the potential danger of smoke hazard, a rational VR based fire training simulator should fully consider all aspects of smoke hazard. In the simulator, the visualization of data based on FDS (Fire Dynamics Simulator) and FED fire dynamic data and volume rendering is further optimized, which can be effectively and quickly applied to virtual fire protection. In addition, a comprehensive smoke hazard assessment model based on FED and FED is established to assess the IHD value of different paths, which represents the safety of different paths, and can be used for evacuation or rescue in virtual training. Taking the case of campus fire drill as an experiment, the research shows the accuracy and effectiveness of smoke assessment based on FDS and FED model. The road force with the highest safety can be selected through the comprehensive model. So the assessment model is proved to be valuable.
基金funded by the National Natural Science Foundation of China (42175171)Humanities and Social Science Research Project of the Ministry of Education of China (20XJC790002)National Key R&D Program of China (2016YFA0602602).
文摘Developing a localized and consistent model framework for climate loss and damage assessment is crucial for the policy-making of climate change mitigation and adaptation.This study introduces a comprehensive,multidisciplinary Integrated Assessment Model(IAM)framework for evaluating climate damage in China,utilizing BCC-SESM climate model and FUND sectoral climate damage model under the SSP2-RCPs scenario.Employing a bottom-up approach,the research estimates climate damage across eight major sectors,recalibrates sectoral climate damage functions and parameters for China,and elucidates distinctions among direct climate loss,market climate loss,and aggregate climate loss.The findings reveal that the total climate damage function for China follows a quadratic pattern in response to temperature rise.By 2050,the estimated climate damage is projected to be 5.4%,5.7%,and 8.2%of GDP under RCP2.6,RCP4.5,and RCP8.5,respectively.Additionally,both direct and market climate losses are projected to remain below 2%of GDP by 2050,while the aggregate climate loss could reach as high as 8.2%,which is predominantly attributed to non-market sectors.From a sectoral perspective,under the RCP8.5 scenario,human health damage constitutes the largest share(61.9%)of the total climate loss by 2050,followed by sea-level rise damage(18.6%).This study sheds lights on the adaptation policy that should attach importance to the non-market sectors,particularly focusing on human health and sea-level rise.
文摘Water yield, water supply and quality, wildlife habitat, and ecosystem productivity and services are important societal concerns for natural resource management in the 21st century. Watershed-scale ecohydrologic studies can provide needed context for addressing complex spatial and temporal dynamics of these functions and services. This study was conducted on the 5240 ha Turkey Creek watershed (WS 78) draining a 3rd order stream on the Santee Experimental Forest within the South Carolina Atlantic Coastal Plain, USA. The study objectives were to present the hydrologic characteristics of this relatively undisturbed, except by a hurricane (Hugo, 1989), forested water-shed and to discuss key elements for watershed management, including water resource assessment (WRM), modeling integrated water resources management, environmental assessment, land use planning, social impact assessment, and information management. Runoff coefficients, flow duration curves, flood and low flow frequency curves, surface and ground water yields were assessed as elements of the WRM. Results from the last 10 years of interdisciplinary studies have also advanced the understanding of coastal ecohydrologic characteristics and processes, water balance, and their modeling including the need of high resolution LiDAR data. For example, surface water dynamics were shown to be regulated primarily by the water table, dependent upon pre- cipitation and evapotranspiration (ET). Analysis of pre- and post-Hugo streamflow data showed somewhat lower but insignificant (α = 0.05) mean annual flow but increased frequency of larger flows for the post-Hugo compared with the pre-Hugo level. However, there was no significant difference in mean annual ET, potentially indicating the resiliency of this coastal forest. Although the information from this study may be useful for comparison of coastal ecohydrologic issues, it is becoming increasingly clear that multi-site studies may be warranted to understand these complex systems in the face of climate change, sea level rise, and increasing development in coastal regions.
文摘Estimation of parameters and random effects using true maximum likelihood methods is compared to the commonly used penalized maximum likelihood method. The simulated catch-at-age datasets have all conceivable noise in stock and fishing dynamics in addition to the observation error on the catch. Improvement is modest in simple models but refinements that are only possible with these methods provide additional precision. Unbiased estimation of natural mortality is made possible with these methods, but precision is low unless variation in fishing effort between years is large and other variation small, in particular the uncertainty in the recruitment. Relatively unbiased estimates of all other in-put parameters and variances were obtained. Alternately the stock may be updated with the catches directly, rather than through the fishing mortality. This can be done exactly and such that bias in the final stock is small. Such a model will test a different error structure and may also be more appealing for presentation of results as the catches are in better agreement with the changes in the estimated stock.
